"Atwood ... says that the inspiration for the question and
answer site began when he read Steve McConnell's Code
Complete: a Practical Handbook of Software Construction. ...
Inspired by McConnell's ideas, Atwood began a blog dedicated
to how programmers could become better at their work that he
called Coding Horror. ...

Maintaining Coding Horror soon
turned into a full-time job, and Atwood started to wonder
what to do next. "What appealed to me most was advancing the
craft in some small way," he says, so he thought of
launching another developer-centered site.

Asking around for
advice, he consulted Joel Spolsky, another prominent
developer turned blogger, who suggested the idea for a
question and answer site. ... Part of the inspiration came
out of the wide-spread dislike of a similar site called
Experts Exchange ... As a result, Stack Overflow went into
private beta in August 2008"